Study of LiNi0.6Co0.2Mn0.2O2 Coated with Li2ZrO3 Nanolayers in All-Solid-State Lithium Ion Batteries

2020 ◽  
Vol 12 (3) ◽  
pp. 412-421 ◽  
Author(s):  
Young-Jin Kim ◽  
Rajagopal Rajesh ◽  
Kwang-Sun Ryu

The Li2ZrO3 nanolayer was coated over LiNi0.6Co0.2Mn0.2O2 cathode material (NCM) to produce all-solid-state lithium ion batteries and their enhanced electrochemical properties were determined. To relieve interfacial resistance resulting from insufficient contact, a Li2ZrO3 nanolayer is a suitable cathode coating agent because it can block corrosive species and decrease contact loss, along with elimination of the space-charge layer. All-solid-state cells using Li2ZrO3-coated NCM material showed higher capacity than pristine NCM. X-ray diffraction patterns showed the same peak separations and lattice parameters as pristine material. Scanning electron microscopy and transmission electron microscopy images obtained with electron dispersive spectroscopy mapping confirmed homogeneous coating with a uniformly thick Li2ZrO3 layer of around 5 nm. X-ray photoelectron spectroscopy revealed that the surface of NCM had two different O1s peaks, with a Zr–O peak, and Ni, Co, Mn, and Zr peaks. Electrochemical studies on pristine and Li2ZrO3-coated NCM materials were conducted using electrochemical impedance spectroscopy with galvanostatic cycle performances by constructing an all-solid-state cell. The impedance spectra showed relieved interfacial resistance with low polarization as coating agent was added. Notably, the 4 wt.% Li2ZrO3-coated NCM exhibited capacity retention of 81% at a current density of 0.12 mA/cm2 after 30 cycles, while that of the pristine cell hadunstable cycle performance and a low capacity retention of 69 percent. Thus, the Li2ZrO3-coated NCM material exhibited potential for all-solid-state batteries requiring high power or stable application.

2014 ◽  
Vol 636 ◽  
pp. 49-53
Author(s):  
Si Qi Wen ◽  
Liang Chao Gao ◽  
Jia Li Wang ◽  
Lei Zhang ◽  
Zhi Cheng Yang ◽  
...  

To improve the cycle performance of spinel LiMn2O4as the cathode of 4 V class lithium ion batteries, spinel were successfully prepared using the sol-gel method. The dependence of the physicochemical properties of the spinel LiCrxMn2-xO4(x=0,0.05,0.1,0.2,0.3,0.4) powders powder has been extensively investigated by using X-ray diffraction (XRD), scanning electron microscope (SEM), charge-discharge test and electrochemical impedance spectroscopy (EIS). The results show that as Mn is replaced by Cr, the initial capacity decreases, but the cycling performance improves due to stabilization of spinel structure. Of all, the LiCr0.2Mn1.8O4has best electrochemical performance, 107.6 mAhg-1discharge capacity, 96.1% of the retention after 50 cycles.


2014 ◽  
Vol 900 ◽  
pp. 242-246 ◽  
Author(s):  
Xing Ling Lei ◽  
Hai Yan Zhang ◽  
Yi Ming Chen ◽  
Wen Guang Wang ◽  
Zi Dong Huang ◽  
...  

LiFePO4/graphene composites were prepared via a simple hydrothermal method. The as-prepared LiFePO4/graphene composites were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), galvanostatic charge-discharge test, cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) tests. The lithium-ion batteries using LiFePO4/graphene composites as cathode material exhibited a discharge capacity of 165 mAh/g, which was 97% of the theoretical capacity of 170 mAh/g.


Ceramics ◽  
2021 ◽  
Vol 4 (3) ◽  
pp. 421-436
Author(s):  
Aamir Iqbal Waidha ◽  
Vanita Vanita ◽  
Oliver Clemens

Composite electrolytes containing lithium ion conducting polymer matrix and ceramic filler are promising solid-state electrolytes for all solid-state lithium ion batteries due to their wide electrochemical stability window, high lithium ion conductivity and low electrode/electrolyte interfacial resistance. In this study, we report on the polymer infiltration of porous thin films of aluminum-doped cubic garnet fabricated via a combination of nebulized spray pyrolysis and spin coating with subsequent post annealing at 1173 K. This method offers a simple and easy route for the fabrication of a three-dimensional porous garnet network with a thickness in the range of 50 to 100 µm, which could be used as the ceramic backbone providing a continuous pathway for lithium ion transport in composite electrolytes. The porous microstructure of the fabricated thin films is confirmed via scanning electron microscopy. Ionic conductivity of the pristine films is determined via electrochemical impedance spectroscopy. We show that annealing times have a significant impact on the ionic conductivity of the films. The subsequent polymer infiltration of the porous garnet films shows a maximum ionic conductivity of 5.3 × 10−7 S cm−1 at 298 K, which is six orders of magnitude higher than the pristine porous garnet film.


Materials ◽  
2021 ◽  
Vol 15 (1) ◽  
pp. 281
Author(s):  
Daniil Aleksandrov ◽  
Pavel Novikov ◽  
Anatoliy Popovich ◽  
Qingsheng Wang

Solid-state reaction was used for Li7La3Zr2O12 material synthesis from Li2CO3, La2O3 and ZrO2 powders. Phase investigation of Li7La3Zr2O12 was carried out by x-ray diffraction (XRD), scanning electron microscopy (SEM) and energy-dispersive x-ray spectroscopy (EDS) methods. The thermodynamic characteristics were investigated by calorimetry measurements. The molar heat capacity (Cp,m), the standard enthalpy of formation from binary compounds (ΔoxHLLZO) and from elements (ΔfHLLZO), entropy (S0298), the Gibbs free energy of the Li7La3Zr2O12 formation (∆f G0298) and the Gibbs free energy of the LLZO reaction with metallic Li (∆rGLLZO/Li) were determined. The corresponding values are Cp,m = 518.135 + 0.599 × T − 8.339 × T−2, (temperature range is 298–800 K), ΔoxHLLZO = −186.4 kJ·mol−1, ΔfHLLZO = −9327.65 ± 7.9 kJ·mol−1, S0298 = 362.3 J·mol−1·K−1, ∆f G0298 = −9435.6 kJ·mol−1, and ∆rGLLZO/Li = 8.2 kJ·mol−1, respectively. Thermodynamic performance shows the possibility of Li7La3Zr2O12 usage in lithium-ion batteries.


2020 ◽  
Vol 10 (3) ◽  
pp. 1021
Author(s):  
Yonglei Zheng ◽  
Yikai Li ◽  
He Wang ◽  
Siheng Chen ◽  
Xiangxin Guo ◽  
...  

We report a novel method to fabricate lithium-ion batteries cathodes with the NH4F pretreatment. In this study, NH4F-pretreated Li1.25Ni0.20Fe0.13Co0.33Mn0.33O2 hollow nano-micro hierarchical microspheres were synthesized for use as cathode materials. The X-ray diffraction patterns of NH4F-pretreated Li1.25Ni0.20Co0.33Fe0.13Mn0.33O2 were analyzed with the RIETAN-FP software program, and the results showed that the samples possess a layered α-NaFeO2 structure. The effects of pretreatment with NH4F on the electrochemical performance of the pristine material were evaluated through charge/discharge cycling, the rate performance, and electrochemical impedance spectroscopy (EIS). Pretreatment with NH4F significantly improved the discharge capacities and coulombic efficiencies of Li1.25Ni0.20Co0.33Fe0.13Mn0.33O2 in the first cycle and during subsequent electrochemical cycling. The sample pretreated with an appropriate amount of NH4F (NFCM 90) showed the highest discharge capacity (209.1 mA h g−1) and capacity retention (85.2% for 50 cycles at 0.1 C). The EIS results showed that the resistance of the NFCM 90 sample (76.32 Ω) is lower than that of the pristine one (206.2 Ω).


Energies ◽  
2020 ◽  
Vol 13 (9) ◽  
pp. 2345
Author(s):  
Maxim Maximov ◽  
Denis Nazarov ◽  
Aleksander Rumyantsev ◽  
Yury Koshtyal ◽  
Ilya Ezhov ◽  
...  

Lithium nickelate (LiNiO2) and materials based on it are attractive positive electrode materials for lithium-ion batteries, owing to their large capacity. In this paper, the results of atomic layer deposition (ALD) of lithium–nickel–silicon oxide thin films using lithium hexamethyldisilazide (LiHMDS) and bis(cyclopentadienyl) nickel (II) (NiCp2) as precursors and remote oxygen plasma as a counter-reagent are reported. Two approaches were studied: ALD using supercycles and ALD of the multilayered structure of lithium oxide, lithium nickel oxide, and nickel oxides followed by annealing. The prepared films were studied by scanning electron microscopy, spectral ellipsometry, X-ray diffraction, X-ray reflectivity, X-ray photoelectron spectroscopy, time-of-flight secondary ion mass spectrometry, energy-dispersive X-ray spectroscopy, transmission electron microscopy, and selected-area electron diffraction. The pulse ratio of LiHMDS/Ni(Cp)2 precursors in one supercycle ranged from 1/1 to 1/10. Silicon was observed in the deposited films, and after annealing, crystalline Li2SiO3 and Li2Si2O5 were formed at 800 °C. Annealing of the multilayered sample caused the partial formation of LiNiO2. The obtained cathode materials possessed electrochemical activity comparable with the results for other thin-film cathodes.


2019 ◽  
Vol 9 (19) ◽  
pp. 4032 ◽  
Author(s):  
Luis Zuniga ◽  
Gabriel Gonzalez ◽  
Roberto Orrostieta Chavez ◽  
Jason C. Myers ◽  
Timothy P. Lodge ◽  
...  

We report results on the electrochemical performance of flexible and binder-free α-Fe2O3/TiO2/carbon composite fiber anodes for lithium-ion batteries (LIBs). The composite fibers were produced via centrifugal spinning and subsequent thermal processing. The fibers were prepared from a precursor solution containing PVP/iron (III) acetylacetonate/titanium (IV) butoxide/ethanol/acetic acid followed by oxidation at 200 °C in air and then carbonization at 550 °C under flowing argon. The morphology and structure of the composite fibers were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS), and thermogravimetric analysis (TGA). These ternary composite fiber anodes showed an improved electrochemical performance compared to the pristine TiO2/C and α-Fe2O3/C composite fiber electrodes. The α-Fe2O3/TiO2/C composite fibers also showed a superior cycling performance with a specific capacity of 340 mAh g−1 after 100 cycles at a current density of 100 mA g−1, compared to 61 mAh g−1 and 121 mAh g−1 for TiO2/C and α-Fe2O3/C composite electrodes, respectively. The improved electrochemical performance and the simple processing of these metal oxide/carbon composite fibers make them promising candidates for the next generation and cost-effective flexible binder-free anodes for LIBs.


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